If I understand the purpose of qacker, I think it would be more useful if it participated in "trackbacks" and other blogospheric/social network like protocols.

There are some blogs that disallow comments, but that do allow trackbacks. This would allow people to more easily add their own comments to such blogs.

There are other blogs that seem to promote anonymity but where, well, it can't quite be trusted up to the blog owner or to the other bloggers at that blog. And qacker with trackbacks would make it easier to comment at those blogs as well.